Accelerated testing method of rapidly evaluating lifespan of fuel cell

Abstract

A method of estimating a lifespan of a fuel cell including a cathode and an anode which contain catalysts and an electrolyte membrane interposed between the anode and the cathode. A cyclic potential with a voltage ranging from a low voltage to a voltage greater than oxidation voltages of the catalysts is applied between the anode and the cathode and fuel cell performance is measured initially and after a predetermined number of cycles. The lifespan of the fuel cell may estimated based on degradation of cell performance after the predetermined number of cycles, based on CV curves obtained during the cycling of the potential and/or a change in particle size of the catalysts after the predetermined number of cycles.

1. An accelerated testing method of evaluating a lifespan of a fuel cell including a cathode and an anode which contain respective catalysts and an electrolyte membrane interposed between the anode and the cathode, the method comprising:
 measuring a cyclic voltammetry (CV) curve of the fuel cell using CV with a scan voltage ranging from a low voltage to a voltage greater than oxidation voltages of the catalysts; 
 a variation in cell performance with respect to a number of CV cycles performed, by investigating a variation in cell potential with respect to the current density of the fuel cell; and 
 determining the lifespan of the fuel cell from a degree of the variation in the cell performance measured, 
 wherein the lifespan of the fuel cell is defined as the number of CV cycles after which the cell potential is reduced to about 25% of the cell potential obtained after 1 CV cycle at a current density of about 200 mA/cm 2 . 
 
     
     
       2. The accelerated testing method of  claim 1 , wherein the scan voltage ranges from 0.3V to 1.5 V. 
     
     
       3. The accelerated testing method of  claim 1 , wherein:
 when measuring the CV curve, a working electrode is the anode and a reference electrode/counter electrode is the cathode, or a working electrode is the cathode and the reference electrode/counter electrode is the anode. 
 
     
     
       4. The accelerated testing method of  claim 1 , wherein the each catalyst is at least one compound selected from the group consisting of PtRu/C, PtRu black, Pt/C, Pt black, PtSn, PtPd, PtNi, PtMo, PtOs and PtCo. 
     
     
       5. The accelerated testing method of  claim 1 , further comprising:
 determining a degree of catalyst aging by observing catalyst particles and morphologic variations. 
 
     
     
       6. The accelerated testing method of  claim 5 , wherein the scan voltage is in a range of 0.3 to 1.5 V. 
     
     
       7. The accelerated testing method of  claim 1 , wherein the scan voltage is in a range of 0.3 to 1.5 V. 
     
     
       8. A method of estimating a lifespan of a fuel cell including a cathode and an anode which contain respective catalysts and an electrolyte membrane interposed between the anode and the cathode, the method comprising:
 performing repetitive potential cycling of the anode relative to the cathode with a scanning voltage ranging from less than an oxidation voltage of the catalysts to greater than the oxidation voltages of the catalysts; 
 measuring a current density of the fuel cell after a first predetermined number of the potential cycles; 
 measuring the current density of the fuel cell after a second predetermined number of the potential cycles; 
 measuring a variation in cell performance with respect to a number of cyclic voltammetry (CV) cycles performed, by investigating a variation in cell potential with respect to the current density of the fuel cell; and 
 determining the lifespan of the fuel cell from a degree of the variation in the cell performance measured, 
 wherein the lifespan of the fuel cell is defined as the number of CV cycles after which the cell potential is reduced to about 25% of the cell potential obtained after 1 CV cycle at a current density of about 200 mA/cm 2 . 
 
     
     
       9. The method of  claim 8 , wherein:
 a rate of change of the scanning voltage is in a range of 20-50 mv/s.